Photocatalytic degradation of acid red-85 dye by nickel substituted bismuth ferrite nanoparticles

Abstract

Visible light driven photocatalytic property of nickel doped BiFeO 3 nanoparticles were explored from the degradation of Acid red-85 dye. Fuel (citric acid) assisted auto-combustion method was adopted for the synthesis of BiFe (1−x) Ni x O 3 (x = 0.25, 0.5, 0.75 and 0.10) nanoparticles. The synthesized particles were characterized by x-ray diffraction, from which reduction in crystallite size has been observed from 57 nm to 28 nm. Lattice parameters also have been calculated for the same which shows an increase in lattice parameters confirming the presence of nickel in the BiFeO 3 lattice. Morphological studies were carried out using high resolution scanning electron microscopy on undoped and 10% nickel doped BiFeO 3 samples which show a decrease in particle size in the doped sample compared to the bare BiFeO 3 similar results have been observed in Transmission Electron Microscopy images. Reduction in the optical band gap from 2.2 eV to 2.02 eV of BiFeO 3 compared to 10% Nickel doped bismuth ferrite is observed. Vibrating sample magnetometer studies performed at room temperature indicates that addition of nickel increases both remnant and saturation magnetization to the bismuth ferrite sample thus helping in the removal of photocatalyst after treatment. Photocatalytic study on the Acid red-85 dye by visible light irradiation showed the complete degradation of dye in 40 min. The 10% Nickel doped BiFeO 3 showed the best photocatalytic activity. The enhancement in the photocatalytic activity of the doped BiFeO 3 is because of efficient charge separation which has been confirmed by photoluminescence studies.